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M. Wagner, K. Stangl, R. Blab:
"Fischer-Tropsch paraffin modified bitumen - performance parameter and reduction of energy consumption";
Talk: ISAP 2008, Zürich; 2008-08-18 - 2008-08-20; in: "ISAP 2008", (2008), ISBN: 978-3-905594-51-5; 197 - 205.

This paper focuses on Fischer-Tropsch (FT) paraffin modified bitumen which are gained by the addition of FT waxes to the base bitumen. Within the testing program two types of bitumen were evaluated for different modifier contents by means of both empirical and performance based test methods in order to determine bitumen performance over the whole service temperature range from -24 °C to 180 °C. The applied methods involve the rotational viscometer for the high temperature range, the dynamic shear rheometer for the intermediate temperature range as well as the bending beam rheometer for the low temperature behavior. Accordingly, the binder´s performance grade values were calculated in order to address the bitumen´s service temperature range. In addition, modulated differential scanning calorimetry was employed to determine bitumen´s thermal behavior allowing to link performance properties to phase-changes of bitumen. Modification leads to hardening of bitumen below the additive´s melting range, whereas above the melting range a distinct viscosity reduction was observed. Consequently, a potential paving temperature reduction could be realized, which might lead to less energy consumption and energy costs. Furthermore, modification leads to a shift of the service temperature range towards elevated temperatures. This implicates a downgrading of the low temperature performance going hand in hand with distinct improved resistance against permanent deformation.

wax bitumen, low-temperature asphalts, low viscosity, performance-based testing